tpmv¶
Computes a matrix-vector product using a triangular packed matrix.
Description¶
The tpmv
routines compute a matrix-vector product with a triangular
packed matrix. The operation is defined as
where:
op(
A
) is one of op(A
) =A
, or op(A
) =A
T, or op(A
) =A
H,A
is ann
-by-n
unit or non-unit, upper or lower triangular band matrix, supplied in packed form,x
is a vector of lengthn
.
API¶
Syntax¶
void tpmv(queue &exec_queue,
uplo upper_lower,
transpose trans,
diag unit_nonunit,
std::int64_t n,
buffer<T,1> &a,
buffer<T,1> &x, std::int64_t incx)
tpmv
supports the following precisions and devices.
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Input Parameters¶
- exec_queue
The queue where the routine should be executed.
- upper_lower
Specifies whether
A
is upper or lower triangular. or not. See Data Types for more details.- trans
Specifies op(
A
), the transposition operation applied toA
. or not. See Data Types for more details.- unit_nonunit
Specifies whether the matrix
A
is unit triangular or not. or not. See Data Types for more details.- n
Numbers of rows and columns of
A
. Must be at least zero.- a
Buffer holding input matrix
A
. Must have size at least (n
*(n
+1))/2. See See :ref:`matrix-storage for more details.- x
Buffer holding input vector
x
. The buffer must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.
Output Parameters¶
- x
Buffer holding the updated vector
x
.